ISO 13490

ISO/IEC 13490 (also known as ECMA-168) is the successor to ISO 9660 (level 3), intended to describe the file system of a CD-ROM or CD-R.

ISO 13490 has several improvements over its predecessor. It fully addresses the filename, POSIX attribute, and multibyte character issues that were not handled by ISO 9660. It is also a more efficient format, permits incremental recording, and permits both the ISO 9660 format and ISO/IEC 13490 format to co-exist on the same media. It also specifies how to use multisession properly.

It is derived from the Frankfurt Group (formed in 1990 by many CD-ROM and CD-WO hardware and media manufacturers, CD-ROM data publishers, users of CD-ROMs, and major computer companies[1]) proposal and fully supports orange book media.

Multiple session overview

ISO 13490 define a rule for operating systems as to how to read a multiple-session ISO 9660 volume from a CD-R. Instead of looking for the volume descriptor at offset 32,768 (sector number 16 on a CD) from the start of the disc (which would be the default behavior in ISO 9660), programs accessing the disc should start reading from the 16th sector in the first track of the latest session. Sector numbers form a contiguous sequence starting at the first session, and continue over added sessions and their gaps.

Hence, if a CD mastering program wants to add a single file to a CD-R that has an ISO 9660 volume, it has to append a session containing at least an updated copy of the entire directory tree, plus the new file. The duplicated directory entries can still reference the data files in the previous session(s).

In a similar way, file data can be updated or even removed. Removal is, however, only virtual: the removed content does not appear any more in the directory shown to the user, but it is still physically present on the disc. It can therefore be recovered, and it takes up space (such that the CD will become full even though appearing to still have unused space).


Though it was originally intended for multisession support only to apply to Mode 2 Form 1 formatted discs, some CD writing software supported multisession writing to Mode 1 format discs. Since only some of the early disc drives supported multisession Mode 1 discs, in many cases the second and following sessions would become unreachable in some drives.

Some older CD writing software, such as Nero Burning ROM, would not import previous session data from an inserted disc. It could thus only write a subsequent session to a disc on the same computer that had written all the previous sessions, and then only if the previous session data was saved before the writing software was closed down.

See also


  1. ^ "Standard ECMA-168" (PDF). ECMA. Retrieved 24 May 2017.

External links


A 5D DVD is a digital storage medium akin to a DVD being developed by Peter Zijlstra, James Chon and Min Gu at the Swinburne University of Technology in Melbourne, Australia. In 2009, the developers estimated that the technology could be commercially ready in five to ten years.

Apple ISO 9660 Extensions

Apple has a set of ISO 9660 Extensions that extends the filesystem with HFS properties. The primary file system for Apple Macintosh computers is HFS (or HFS+).

The HFS file system has more properties than FAT file systems (which are primarily used on Windows 95 and 98 operating systems). Some of the metadata properties include:

Date of last backup

File type

Creator code

Flags and data for display

Reference to a resource forkIn order to allow non-Macintosh systems to access Macintosh files on CD-ROMs, Apple chose to use an extension of the standard ISO 9660 format. Most of the data, other than the Apple specific metadata, remains visible to operating systems that are able to read ISO 9660.


CD-Text is an extension of the Red Book Compact Disc specifications standard for audio CDs. It allows for storage of additional information (e.g. album name, song name, and artist name) on a standards-compliant audio CD.

The specification for CD-Text was included in the Multi-Media Commands Set 3 R01 (MMC-3) standard, released in September 1996 and backed by Sony. It was also added to new revisions of the Red Book. The actual text is stored in a format compatible with Interactive Text Transmission System (ITTS), defined in the IEC 61866 standard. The ITTS standard is also applied in the MiniDisc format, as well as in Digital Audio Broadcasting technology.


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DVD-Ds, also referred to as disposable DVDs, are a type of digital video disc that is designed to be used for a maximum 48 hours after the containing package is opened. After this time, the DVDs become unreadable to DVD players because they contain a chemical that, after the set period of time, will prevent the underlying data from being read by DVD drives. The medium in itself is copy protection neutral and does not require additional Digital Rights Management types of applications to be installed for the content to be accessible. The technology used for DVD-Ds is different from that for earlier disposable DVDs. DVD-D has a reservoir in the central area of the disc which contains the chemical agent. When the disc spins for the first time the chemical agent moves and gets in contact with the reflective layer of the disc. After approximately 48 hours, the reflective layer becomes unreadable as the laser cannot reflect on the layer.

El Torito (CD-ROM standard)

The El Torito Bootable CD Specification is an extension to the ISO 9660 CD-ROM specification. It is designed to allow a computer to boot from a CD-ROM. It was announced in November 1994 and first issued in January 1995 as a joint proposal by IBM and BIOS manufacturer Phoenix Technologies.

Forward Versatile Disc

Forward Versatile Disc (FVD) is an offshoot of DVD developed in Taiwan jointly by the Advanced Optical Storage Research Alliance (AOSRA) and the Industrial Technology Research Institute (ITRI) as a less expensive alternative for high-definition content. The disc is similar in structure to a DVD, in that pit length is the same and a red laser is used to read it, but the track width has been shortened slightly to allow the disc to have 5.4 GB of storage per layer as opposed to 4.7 GB for a standard DVD. The specification allows up to three layers for total of 15 GB in storage. WMV9 is used as the video codec allowing for 135 minutes of 720p video on a dual layer disc and 135 minutes of 1080i video on a three-layer disc. FVD uses AACS copy protection which is one of the schemes used in both HD DVD and Blu-ray Discs.

An FVD disc can either be an FVD-1 or FVD-2 disc:

FVD-1: The coding format of the first generation of FVD adopts 8/16 modulation codes (same as DVD).

FVD-2: The second generation will use the more efficient 8/15 coding for increasing the ECC capability (to avoid DVD patents).

Frankfurt Group (disambiguation)

The Frankfurt Group was a group of 19th Century musicians.

The Frankfurt Group may also refer to:

The "Frankfurt group", a group of al-Qaeda-affiliated terrorists responsible for the Strasbourg Cathedral bombing plot in December 2000

The Frankfurt Group, proposers of ISO 13490 CD-ROM file system

The Frankfurt group, involved in the Troubles at Frankfurt in the mid-1550s,


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ISO 9660

ISO 9660 is a file system for optical disc media. Being published by the International Organization for Standardization (ISO) the file system is considered an international technical standard. Since the specification is available for anybody to purchase, implementations have been written for many operating systems.


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List of DVD authoring software

The following applications can be used to create playable DVDs.


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The 8 cm optical disc format was originally used for music CD singles, hence the commonly used names CD single and miniCD. Similarly, the manufactured 8 cm DVDs were originally used for music videos and as such became known as DVD single.

MiniDVD is known also as "3 inch DVD", referring to its approximate diameter in inches.

Packet writing

Packet writing (or incremental packet writing, IPW) is an optical disc recording technology used to allow write-once and rewritable CD and DVD media to be used in a similar manner to a floppy disk from within the operating system.

Rainbow Books

The Rainbow Books are a collection of CD format specifications.

SCSI Multimedia Commands

SCSI Multimedia Commands (MMC) defines a SCSI/ATAPI based command set for accessing multimedia features on devices capable of such functionality. T10 subcommittee is responsible for developing it as well as other SCSI command set standards.

Stacked Volumetric Optical Disc

The Stacked Volumetric Optical Disc (or SVOD) is an optical disc format developed by Hitachi/Maxell, which uses an array of wafer-thin optical discs to allow data storage.

Each "layer" (a thin polycarbonate disc) holds around 9.4 GB of information, and the wafers are stacked in layers of 100 or so, giving overall data storage increase of 100× or more.

SVOD might likely be a candidate, along with HVDs, to be a next-generation optical disc standard.

Standards of Ecma International
Application interfaces
File systems (tape)
File systems (disk)
Programming languages
Radio link interfaces
ISO standards by standard number

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